The anti-cancer effect of the antimalarial agent chloroquine when combined with conventional chemotherapy has been well documented. To date, it was assumed that chloroquine increases the sensitivity of cancer cells to chemotherapy by means of a direct effect on the cancer cells. However, a recent study has demonstrated that chloroquine also normalizes the abnormal blood vessels in tumors. This blood vessel normalization results in an increased barrier function on the one hand, and in enhanced tumor perfusion on the other hand, which increases the response of the tumor to chemotherapy.

Source: Malaria medicine chloroquine inhibits tumor growth, metastases, study shows